The present invention relates to a method and/or architecture for control of output drive strength generally and, more particularly, to a method and/or architecture for an on-chip circuit to compensate output drive strength across process corners.
Many applications require circuits that are insensitive or less sensitive to process variations. An example of such a application is an output buffer circuit that reduces noise across process corners.
Output drivers are generally designed to meet speed requirements at a slow process corner. An output driver designed for a slow process corner generates a lot of noise at fast corners. There is a trade off between meeting speed requirements at slow corners and keeping noise well under control at fast corners. An on-chip circuit to provide compensation for process variations would be desirable.
The present invention concerns an apparatus comprising a first circuit, a second circuit, and a third circuit. The first circuit may be configured to generate a first signal having a first frequency. The second circuit may be configured to generate a second signal having a second frequency that is generally a function of a process variation. The third circuit may be configured to control a process variation sensitive parameter in response to the first and second signals.
The objects, features and advantages of the present invention include providing an apparatus, method and/or architecture for an on-chip circuit to compensate output drive strength across process corners that may (i) make design of the output driver very simple, (ii) cut down the design cycle time drastically, (iii) improve performance of output drivers in terms of speed and noise requirements, (iv) be used to control any circuit parameter that is a function of process corners, (v) help keep more constant characteristics on output drivers, and/or (vi) provide a digital solution for compensating for process corners as opposed to an analog solution.